1. Field of the Invention
The present invention relates to a sealing resin sheet, a method for producing an electronic component package and an electronic component package.
2. Description of the Related Art
In recent years, downsizing, weight reduction and function enhancement of electronic instruments have been increasingly required, and accordingly downsizing, thickness reduction and high density mounting have been desired for packages that form electronic instruments.
For preparation of an electronic component package, typically a procedure is employed in which electronic components that are fixed to a substrate, a temporary fixing material or the like are sealed with a sealing resin, and the sealed product is diced as necessary so that a package is formed per each electronic component. For meeting the above-described requirement, in the course of this process, a technique of reducing the thickness by grinding (back-grinding) a sealed product after resin sealing has been proposed (for example Japanese Patent No. 3420748, Japanese Patent No. 3666576, etc.). The thickness reduction by grinding as described above is also an important factor in production processes of thin semiconductor packages such as a flip chip BGA (Ball Grid Array), a flip chip SiP, a fan-in wafer level package and a fan-out wafer level package.
However, when a sealed product is ground, a sealing resin may be dragged by a grinding member such as a grindstone to generate thread-like grind wastes, or quality degradation of a ground surface by deposition of grind wastes on a semiconductor chip and a bump surface or the like, or damage to the grinding member, or the like may occur. It is required not only to merely perform grinding but also to make the ground surface smooth and flat. This is because if an unevenness of the ground surface is too large, precise mounting of electronic components becomes difficult, or cracking or the like of a sealed body occurs due to the unevenness during heat treatment in a subsequent step. Since problems associated with grinding as described above, and smoothing and flattening are not recognized in Japanese Patent No. 3420748 and Japanese Patent No. 3666576, specific solutions are desired.